Association between Coffee and Green Tea Consumption and All‐cause and Cause‐specific Death

Abstract

Background: Both coffee and green tea are popular beverages worldwide. However, the effect of these beverages on death remains unclear. Therefore, we aimed to investigate the association between coffee and green tea drinking and all‐cause and cause‐specific death. Materials and Methods: The Korean Multi‐center Cancer Cohort (KMCC) study, a population‐based prospective cohort study, commenced from 1993 to 2005. Death was ascertained by means of linkage to Nationwide Death Certificate database in Korea until December 31, 2014. We used 11,877 individuals (4,615 men and 7,262 women) for analysis. The risks of all‐cause, cancer, cardiovascular disease and other particular caused death were assessed by estimating hazard ratios (HRs) and their 95% confidence intervals (95% CIs) using cox proportional hazard model adjusted for potential confounders such as age, sex, cigarette smoking, alcohol consumption, body mass index and comorbidity index (consisted of history of bronchopneumonia, chronic liver disease, hypertension, ischemic heart diseases, stroke and diabetes). Results: 2,326 participants (1,331 men and 995 women) died until the end point of follow-up (December 31, 2014). Multivariate adjusted HRs (95% CIs) for all‐cause death were 0.91 (0.81 - 1.03) for 2-4 cups of coffee/month, 0.79 (0.69 - 0.91) for 2-6 cups of coffee/week, 0.83 (0.75 - 0.92) for 1≤cup of coffee/day (p for trend<0.001) compared with those who drank ≤1 cup of coffee/month. Corresponding to green tea, multivariate adjusted HRs (95% CIs) were 0.94 (0.84-1.06), 0.82 (0.70-0.96) and 0.76 (0.63-0.93) (p for trend<0.001). Inverse association were also observed between coffee drinking and death due to chronic liver disease. As compared person who drank ≤1 cup of coffee/month, multivariate adjusted HRs (95% CIs) for chronic liver disease related death were 0.88 (0.44-1.77) for 2-4 cups of coffee/month, 0.47 (0.18-1.22) for 2-6 cups of coffee/week, 0.51 (0.27-0.97) 1≤cup of coffee/day. Neither coffee nor green tea drinking were not significantly associated with cancer death. Conclusions: Our community based prospective cohort study suggested that coffee and green tea drinking was associated with reduced risk of all‐cause death. Furthermore, coffee drinking was inversely associated with chronic liver disease related death.